1994 Chevy S10 Blazer 4 door 4x4. 4.3L Vortec. Question: Hello, I have been having a lot of trouble with my Chevrolet Blazer and i desperately need some help i have 3 questions that i hope you can help me with:
1. I replaced the fuel pump and now my gauge always reads full.
2. Replaced plugs and wires but engine still feels like it is chugging.
3. Getting very bad gas mileage, put 25.00 worth of fuel in and the truck died after 17L/49 km
Please Help!!!

Answer: OK. Well, if after replacing the fuel pump you have no fuel gauge, then either you forgot the connect the wires for the level sensor, the new pump module did not come with a sensor and you did not switch it, the wires for the connector on top of the tank got messed up or the sensor itself is bad. That is very common for these.

Number two and three sound related. If new spark plugs and plug wires did not fix the way the engine is running, you may have a bad distributor cap and rotor, or in relation to number three- a fuel problem. You are using way too much gas. This would also cause it to run bad and misfire, and possibly a check engine light. A common problem on this 4.3L Vortec is a leaking fuel pressure regulator (FPR), stuck open fuel injectors(s) or broken fuel lines under the upper intake manifold. Either one would cause a very rich condition and cause the engine to run bad. You may also notice that the oil level is overfull or smells like gas. If this is the case, you need to take the upper intake off and inspect the regulator and lines and injectors. Replace what has failed and change the oil or engine bearing damage will occur.